The long-term goal of this research is to reduce the risk of falls in the elderly by improving their postural control during locomotion. Specifically, this research will focus on how the nervous system makes use of cane for postural stability during gait in patients with central and peripheral balance impairments. Specific aim 1. To determine the most effective method of obtaining somatosensory cues for balance through the use of a cane during walking. Experiment 1will be conducted to determine how elderly subjects should use a cane to maximize the use of somatosensory inputs from the hand. In this experiment, elderly subjects will be asked to perform 2 methods of cane usage;1) lightly pushing on a long cane continuously on the floor, as a blind person uses the cane to assist in orientation through space and 2) lightly touching the cane intermittently on the floor, only when the opposite foot is in the stance phase. A postural perturbation will be induced by translating the support surface on random trials during heel strike phase of walking. During the experiment, the reliance on vision will be reduced by wearing dark, shaded sunglasses. We predict that the intermittent method of cane usage will show more improvement in balance. Specific aim 2. To determine the extent to which sensory inputs from use of a cane while walking benefit subjects with impaired peripheral sensory inputs or impaired central sensorimotor integration. Experiment 2 will assess the benefits of sensory cues from light touch through a cane in improving postural control in patients with peripheral or central, somatosensory disruption due to diabetes neuropathy or Parkinson's disease. We predict that additional sensory cues from the cane will improve postural control in patients with peripheral sensory loss but not in patients with sensorimotor integration deficits due to Parkinson's disease. The methods of cane use in Experiment 1 will be used to assist postural control during surface perturbations at the heel strike phase of walking with vision reduced. PUBLIC HEALTH RELEVANCE: This study will lead to the development of novel rehabilitative strategies that can be suggested to elderly patients who have postural control disorders due to sensory impairments.